Improving crop yield from agriculturally significant plants including, among others, corn, soybean, sugarcane, rice, wheat, vegetables, and cotton, has become increasingly important. In addition to the growing need for agricultural products to feed, clothe and provide energy for a growing human population, climate-related effects and pressure from the growing population to use land other than for agricultural practices are predicted to reduce the amount of arable land available for farming. These factors have led to grim forecasts of food security, particularly in the absence of major improvements in plant biotechnology and agronomic practices.
Insects, particularly insects within the order Lepidoptera, are considered a major cause of damage to field crops, thereby decreasing crop yields over infested areas. Lepidopteran pest species which negatively impact agriculture include, but are not limited to, Helicoverpa zea, Ostrinia nubilalis, Diatraea saccharalis, Diatraea grandiosella, Anticarsia gemmatalis, Spodoptera frugiperda, Spodoptera exigua, Agrotis ipsilon, Trichoplusia ni, Chrysodeixis includens, Heliothis virescens, Plutella xylostella, Pectinophora gossypiella, Helicoverpa armigera, Elasmopalpus lignosellus, Striacosta albicosta and Phyllocnistis citrella. 
Strains of the bacterium Bacillus thuringiensis (Bt) have historically been used as a source for proteins which exhibit pesticidal activity. For the past seventy years, Bt-derived toxin proteins have been employed in various agricultural applications to preserve agriculturally important plants and increase yields. Bt-derived insect inhibitory proteins are used to control agriculturally-relevant pests of crop plants by mechanical methods, such as spraying to disperse microbial formulations containing various Bt strains onto plant surfaces, and by using genetic transformation techniques to produce transgenic plants and seeds expressing Bt toxin protein.
The use of transgenic plants expressing Bt toxin proteins has been globally adapted. For example, in 2012, 26.1 million hectares were planted with transgenic crops expressing Bt toxins (James, C., Global Status of Commercialized Biotech/GM Crops: 2012. ISAAA Brief No. 44). The expanded use of transgenic insect-protected crops and the limited number of commercially available Bt toxin proteins is creating a selection pressure for alleles that impart resistance to the currently-utilized Bt proteins. The development of resistance in target pests to Bt toxin proteins undermines the effectiveness and advantages of this technology. Such advantages include increased crop yields, reduction in chemical pesticide use, and reduction in the costs and labor associated with chemical pesticide use.
The development of new forms of toxin proteins is central to managing the increase in insect resistance to transgenic crops expressing Bt toxin proteins. New protein toxins with improved efficacy and which exhibit control over a broader spectrum of susceptible insect species will reduce the number of surviving insects which can develop resistance alleles. In addition, two or more transgenic toxins, both toxic to the same insect pest and displaying different modes of action when expressed in a single plant, further reduces the probability of the development of resistance to either toxin by the target insect species.
Consequently, there is a critical need to discover and develop insecticidally effective toxin proteins with improved insecticidal properties such as increased efficacy against a broader spectrum of target insect pest species and different modes of action compared to proteins known in the art. A novel protein toxin TIC2160 is disclosed herein along with other similar toxin proteins, variant proteins, and exemplary recombinant proteins similar to TIC2160, that each exhibit insecticidal activity against significant target Lepidopteran pest species.